Endocytosis is a complex process of absorption from the environment (and subsequent distribution within the cell) of soluble substances, macromolecules, microparticles, etc. by means of vesicles developed by cytoplasmic membrane. Endocytosis in animal and human cells is actively and successfully studied. Thus, classification of this process in the animals (based only on the peculiarities of primary vesicle formation) includes up to ten different endocytosis pathways. Modern knowledge about endocytosis in mycelial fungi is not so extensive; therefore, its study in this group of organisms is a topical and promising direction in fundamental and applied mycology. In the present work, we studied the effect of six different inhibitors (acting both on the assembly of actin/tubulin cytoskeleton and on the formation of different types of endocytosis) on the dynamics of endocytosis in phytopathogenic heterobasidial fungus Rhizoctonia solani. The estimation of the effect of inhibitors was conducted by means of microscopic analysis of the absorption of the fluorescent marker of endocytosis AM4-64 by mycelial cells. As a result of the conducted study, four types of the inhibitor effect on the R. solani endocytosis were detected: from the complete absence of the effect to severe suppression of different stages of fungal endocytosis. It was found that four of six inhibitors used for the suppression of endocytosis in the animals and human have a suppressive effect on endocytosis of R. solani. This indicates the conservative nature of some endocytosis mechanisms in the studied fungus and probably in mycelial fungi in general. Different hypotheses concerning principles of the effect of studied inhibitors on endocytosis activity of fungi were suggested.
Lichen are symbiotic systems constituted by heterotrophic fungi (mycobionts) and photosynthetic microorganism (photobionts). These organisms can survive under extreme stress conditions. The aim of this work was to study the influence of low (−70°C) or high (+70°C) temperatures, temperature fluctuations from +70°C to −70°C, and anaerobic conditions on P. aphthosa (L.) Willd. viability. None of the studied stress factors affected significantly photosynthetic and respiratory activity of the thalli. No changes in morphology or ultrastructure of the cells were revealed for both photobiont and mycobiont components after extreme temperature treatment of P. aphthosa thalli. The data show the extreme tolerance of P. aphthosa to some stress factors inherent to the space flight conditions.
The review is devoted to the endomembrane system in Fungi, which is mostly presented in cell by membrane organelles, taking part in exo- and endocytosis. Main tenets of the modern model of exo- and endocytosis are covered by the example of the apical cells of filamentous fungi. Particular attention is given to studies of endomembrane system, which were carried out by electron microscopy in the last century--the era in science preceding the prevalence of methods of fluorescence microscopy, immune and molecular genetic tagging. Endomembrane organelles, which are described in classical studies, but have not been identified or differentiated from other organelles modern specialists are under consideration. Among these organelles are lomasomes, plasmalemmasomes, membranosomes and myelin-like bodies. Possible reasons for the "loss" of given structures in today's science and its place in modern proposed model of endomembrane system are discussed. In addition, some specific questions are mentioned, namely: the presence of mushroom mycelium endobionts, morphologically similar to endomembrane organelles, and the increase of number of endomembrane structures in bracket fungi, limited in nitrogen nutrition.
Многолетние микробиологические исследования пыльцы березы повислой, произрастающей на территории Москвы и Московской области, показали, что около трети проанализированных образцов содержат гриб, идентифицированный нами по морфолого-культуральным и молекулярно-генетическим критериям как Quambalaria cyanescens (de Hoog & G.A. de Vries) Z.W. de Beer, Begerow & R. Bauer. Данный вид ранее был известен преимущественно как симбионт тропических растений родов Eucalyptus и Corymbia и на территории России раньше не выделялся. Нами впервые установлена тесная ассоциация вида Q. cyanescens с березой повислой. Показано, что микромицет регулярно обнаруживается не только в пробах пыльцы, но на поверхности и внутри сережек, на поверхности листьев и веток березы, при этом не выделяется с других видов растений из районов проведенного исследования. В статье приведены морфолого-культуральные характеристики, особенности ультраструктуры клеток, данные по встречаемости гриба, а также филогенетический анализ выделенных штаммов.
Long-term microbiological investigation of the pollen of silver birch (Betula pendula) in the Moscow and Moscow oblast areas revealed that almost one-third of the analyzed samples contained the fungus identified by morphological, cultural, and molecular genetic techniques as Quambalaria cyanescens (de Hoog & G.A. de Vries) Z.W. de Beer, Begerow & R. Bauer. This species was previously known mostly as a symbiont of tropical plants of the genera Eucalyptus and Corymbia and have not been isolated in Russia. We revealed a close association between Quambalaria cyanescens and silver birch. The micromycete was regularly detected in pollen samples, as well as on the inside and outside of the aments, and on the surface of leaves and branches. It was never isolated from other plant species in the investigated area. The data on the morphological and cultural characteristics of the fungus, its cell ultrastructure, and occurrence are presented, as well as the phylogenetic analysis of the isolated strains.
Twenty-one strains belonging to 18 species of basidiomycetes from different ecological groups of fungi were isolated from natural sources. Light and electron microscopy was used to determine the morphological properties of the cultures, which confirmed their classification as basidiomycetes and facilitated their identification in monocultures. The capacity of the fungal strains for biosynthesis of antibiotics was determined by one- or two-stage cultivation on seven nutrient media. It was established that, under submerged cultivation, antimicrobial substances were formed by 13 strains (81.25%) of 12 fungal species ( Armillaria sp., Coprinus comatus, Flammulina velutipes, Hypsizygus ulmarius, Lentinus tigrinus, Lycoperdon pyriforme, Macrolepiota procera, Panellus serotinus, Pholiota aurivella, Pholiota lenta, Rhodocollybia maculate , and Sparassis crispa ). The antibiotics formed were efficacious against bacterial test strains, including the methicillin-resistant strain Staphylococcus aureus (MRSA) and the strain Leuconostoc mesenteroides VKPM B-4177 that is resistant to the glycopeptide antibiotics. No antibiotic activity was revealed against fungal test cultures ( Aspergillus niger INA 00760 and Saccharomyces cerevisiae RIA 259).